Jung's concept of the collective unconscious differs from Freud's concept of the unconscious in that: a) Jung's collective unconscious is entirely personal, while Freud's unconscious is universal. b) Jung's collective unconscious contains archetypes, while Freud's unconscious contains repressed desires. c) Jung's collective unconscious is not influenced by childhood experiences, while Freud's unconscious is. d) Jung's collective unconscious is a surface level of consciousness, while Freud's unconscious is deep-seated.